从理论和应用两方面对光学薄膜吸收缺陷的检测方法进行了研究。基于CCD摄像机的图像锁相技术, 提出了不同于传统逐点扫描方法的多通道薄膜吸收检测方法。基于逐点扫描法和图像检测法, 分别计算了大区域内薄膜单点缺陷所对应的吸收分布, 结果证明了图像法应用于较大口径薄膜元件吸收检测的可行性。计算和实验表明：相对于逐点法, 图像法测量薄膜速度可以提高上百倍, 避免了逐点扫描法中耗时长、效率低的不足, 扩展了光热技术在大口径镀膜光学元件中的应用。

The absorption detection of optical coatings is studied in theory and application. A novel method of multichannel measurement based on image lock-in is presented. The comparison between the calculated measuring results of point by point method and multichannel method is made, which proves the feasibility of the multichannel method for large scaled coatings measurement. Through calculation, it is known that the measuring speed of image method can be increased more than hundreds of times compared with that of the past. This technique avoids the weakness of long time-consuming and low efficiency in traditional method and expands the application of photothermal technique in large scale optical coatings.